This invention is directed generally to analog-to-digital and digital-to-analog (AD/DA) conversion systems and high speed processing, and more particularly to a 1-bit high speed signal processing method and system. The application also addresses an application of such signal processing in recording, broadcasting, sound reenforcement, musical instruments, video signal processing and active control of sound and vibration.
In digital signal processing, the effect of finite word length must always be taken into consideration. In AD/DA conversion, the limitations of finite word length appear generally as quantization noise which diminishes the quality of the conversion and accuracy of reproduction of the original analog signal following AD/DA processing. While a number of types of AD/DA converters have been utilized, more recently a Sigma Delta modulation type converter has been developed, which concentrates quantization noise in the high frequency areas by setting a quantizer in the feedback loop. This may be especially useful in audio applications wherein the bulk of the useful information is in the lower frequency portion of the spectrum. The delay experienced in digital signal processing has always posed a problem, particularly in active control of audio sound fields.